Inductive rotary transmitters are known in various embodiments. For example, DE 202 04 584 U1 or DE 101 07 577 A1 each disclose a rotary transmitter, wherein the stator and the rotor each have a winding and each have a magnetisable core. The rotor and the stator are arranged coaxially with one another.
An inductive rotary transmitter is known from DE 10 2006 020 808 A1. At least the rotor or the stator has a carrier made of plastics material having soft-magnetic particles, which carries the associated coil.
The rotary transmitter known from DE 26 57 813 A1 has two cores arranged concentrically with one another, each having a winding. The rotary transmitter serves to transmit electrical signals. The stator winding and the rotor winding are each applied to a substrate as an endless coil in the manner of a printed circuit. The windings are each glued into a groove in the associated hollow-cylindrical ferrite core.
A further exemplary embodiment of an inductive rotary transmitter is described in WO 2013/072373 A1. The stator core there has two stator limbs extending parallel to one another, in each of which a rotary bearing is provided. The rotor is arranged between the two limbs of the stator core and has a rotor core and a rotor winding. The two parallel stator limbs are connected to one another by a connection limb extending transversely thereto, on which connection limb a stator winding is arranged. In one exemplary embodiment each stator limb may have integrally formed limb parts, which are arranged in a cross-shaped manner and which intersect one another in the region of the axis of rotation of the rotor.
In the case of the inductive rotary transmitter described from DE 20 2010 012 270 U1 the stator winding and the rotor winding are arranged concentrically with the axis of rotation. The windings may be arranged axially side by side or concentrically with one another. Each winding is assigned a magnetisable core. In a modification, it is also possible to use air coils without core.
For transmission, a magnetic circuit is produced between the stator winding and the rotor winding in the case of inductive rotary transmitters, wherein the magnetic field lines are guided via a magnetic circuit having magnetisable cores on the stator side and rotor side. In order to ensure the efficiency of the inductive energy transmission, the parts of the magnetic circuit moving relative to one another must be manufactured and mounted very accurately. In order to achieve a uniform energy transmission in the circumferential direction about the axis of rotation of the rotor at the air gap of the magnetic circuit, the magnetisable cores of the stator and of the rotor are continuous and in particular rotationally symmetrical in the circumferential direction about the axis of rotation of the rotor.